The Substitute
by Editor-Bug
Summary: When Ms. Bitters goes on vacation, she is replaced by a substitute named Ms. Olive. But Dib suspects there is more to her than meets the eye. Also, Zim is really creepy. ONE-SHOT! Read & review if you like! Rated T for Zim being creepy. You've been warned.


"And that is where babies come from," concluded Ms. Bitters. "Any questions?"

Everyone else in the room looked traumatized besides Dib; his dad had told him all about this stuff years ago, thus ruining his childhood forever. And then there was Zim, who was creepily intrigued.

He raised his hands. "Yes, I have a question, and a follow-up question. Since the way out is so small, do the human babies sometimes get stuck in th- -"

The screams of the other students prevented Zim from going further.

"Zim, that's disgusting. Put your other hand down, your follow-up question is now invalid. Any _other_ questions? No? Good, listen up, I have some relatively good news," Ms. Bitters announced.

"You're retiring?!" guessed Melvin.

"You're giving out free glitter stickers?!" guessed Gretchen.

"You're PREGNANT?!" Zim guessed far more loudly than was necessary. Everybody turned to stare at him. "What? You were all thinking it!"

"No, definitely no, and stop talking," Ms. Bitters pointed at the guessers. "My news is that the school board has finally allowed me a break from teaching you little nightmares. So, while I spend next week in the teachers' lounge, you all will have a substitute teacher."

The students rejoiced, unable to remember the last time they'd had a substitute teacher. Probably because this was the first time they were going to have a substitute teacher.

"Ms. Bitters, why are you spending your time off in the teachers' lounge? Shouldn't you go home?" asked Dib.

"Silence, Dib-human!" Zim snapped at him. "It is Ms. Bitters's business where she chooses to give birth to her stink children! Right, Ms. Bitters?"

The teacher raised an eyebrow. "Uh...sure."

Zim pumped his fist, smiling to himself. "I knew it..."

The bell rang, signaling that another day of learning had finally come to a close.

XXXXXXXMONDAYXXXXXXX

After arriving at Skool on Monday, Dib was surprised to find his classroom far more empty, gray and barren than usual. Even though there had been a bunch of people there just a couple days ago, it looked like the place hadn't been touched in years. And then there was Zim, who was sitting at his desk looking like a wreck.

His wig was messy, his hands were shaking in his gloves, he was sweating and his face was flushed.

"Where...is everybody?" Dib asked him. "And what happened to you?"

Suddenly, Zim took notice of the human.

"Oh! Hello, Dib," he greeted awkwardly. "H-How are you?"

"...I just asked where everyone is. And what is your deal?!"

Zim slid out of his seat. "Oh, I just spent the entirety my weekend researching human anatomy, sexuality, mating rituals and whatever else."

Dib flinched as Zim grabbed him by the shoulders, looking him up and down.

"The human body is such a beautiful thing..."

"AHHHHHH!" Dib ran out of there for his life.

"Wait! Come back!" Zim called after him. "Lemme see in there!"

"AHHHH- -OOF!" Dib bumped into someone as he rounded a corner.

As it turned out, it was a rather tall young woman with long, magenta hair. She was wearing a yellow women's business suit and heels, and strangely enough, she had all of Dib's classmates in a herd behind her.

"Uh-oh," she spoke in a gentle voice. "Are you lost?"

"Huh?" Dib collected himself as the lady gave him a smile. "Are you our substitute teacher?"

"You betcha! Ms. Olive, at your service!" she sang.

"Well, you have to help me! This kid in our class, Zim- -he's an alien, by the way- -has gone crazier than usual and he was- -"

"A-ha-ha!" Ms. Olive ruffled his hair. "Aren't you just an adorable little pack of pistachios? Come now, children, to the classroom~!"

Agitated, Dib straightened out his hair, but he followed her anyway, along with all the other kids. When they reached Ms. Bitters's classroom, Zim lecherously stared at everybody who walked in.

"Alright, class! While your teacher, Ms. Bitters, is," she coughed and paused suddenly, which caused Dib to raise an eyebrow. "Occupied, I, Ms. Olive, will be taking over for your class. She'll be back before you know it~!"

 _"Well...think about it,"_ Dib said in his head for once. _"She seems nice. The singing is sort of annoying, but she's nice. Maybe this week will be fine after all!"_

But over the course of the class, things got kinda weird. Nobody in Skool had made fun of Dib or called him crazy all day. In fact, they seemed quite happy, and that was most definitely odd.

Maybe they liked Ms. Olive's singing a lot more than they should have.

Or maybe, just MAYBE- -

"Ow!" Dib flinched as a wad of paper smacked him in the head.

He unfolded it, and shakily written on it was: "DIB, MEET ME OUTSIDE AFTER SKOOL -ZIM!"

Dib shuddered and threw the note over his shoulder, hitting Old Kid (who barely reacted) in the face. He tried not to look at Zim.

"HEAD BANGIN', YEAHHH!" Poonchy screamed beside him.

"Hey, uh, what are we supposed to be doing right now?" Dib whispered. "Ms. Olive has just been sitting there, humming and eerily rocking her head side to side for twenty minutes."

"I dunno!" Poonchy shrugged. "I'm just...enjoying life right now!"

Dib's eyes widened to nearly impossible measurements. "Enjoying...life...?"

Without even asking for a hall pass, Dib dashed out of the classroom. He could've sworn he saw Zim staring after him...

"Enjoying life!" Dib repeated once he was in the privacy of a bathroom stall. "There's no way there isn't anything paranormal going here! Ms. Olive is not a substitute teacher! She's some sort of siren sorceress, trying to control our class! ...which is pretty much what a teacher does, but she SINGS!"

He piped down when he heard the door to the bathroom open. Peeking under the stall door, Dib recognized Zim's boots and hid by perching upon the toilet seat and pulling his knees up to his chest. That way, Zim wouldn't be able to peek at him from under the stall.

Outside the stall, Zim faced the mirror and fixed himself up. "Ahh...won't be long now. Ms. Bitters has been impregnated by her hatred of our class, as all human smeets are conceived! And once I capture that beautiful, STUPID Dib, I shall harvest the sperm from his brain-meats, it shall induce her to give birth, and that human worm-baby I shall raise as my own offspring, and train it to DESTROY HUMANS! AHAHAHAHAHAHA! And all whilst observing humans in their natural birth cycle! Education-evil!"

It then occurred to Dib that Zim's knowledge on human reproduction was pretty far off. Well, what did he expect? He gasped silently as he heard the door to the bathroom open again.

"Oh, Zim!" Ms. Olive's voice rang out.

"SIR!" Zim responded.

"Come on back to class now, dear!"

Dib heard Zim go marching out of the restroom, but he could tell Ms. Olive had stayed behind. Slowly, but surely, those yellow heels of hers made their way in front of Dib's stall.

Sweat leaked out of every pore on his face. He pulled his knees up even higher. He held his breath.

"You head back to class too," the woman said in an unusually stern tone. Then she exited the boys' room.

Dib allowed his breath to escape him. Ever more frightened, he hesitantly returned to the classroom.

After that disturbing school day had finally ended, Dib tried to avoid Zim on his way out of the building. No such luck.

"Dib!" Zim called, running to follow him.

"Look, Zim, will you just stay away from me?!" the boy snapped. "At least until your creepy obsession blows over!"

"B-But! This is about that substitute-human!"

"You mean Ms. Olive?"

"Yes! I noticed your contempt for her, and I would like to help you get rid of her!"

"Yeah, right! Like you would ever help me, aside from those times when you did! You just wanna kidnap me and harvest my sperm or whatever!"

Zim looked offended. "What makes you think I would do such a thing?"

"Just leave me alone, Zim," grumbled Dib. He turned and walked away.

XXXXXXXXXXXXXXXXXXXXXX

The next couple of days, Dib didn't make much progress on his case. While Ms. Olive continued her whole creepy song thing, at least she didn't seem to be hurting anyone. And Zim wasn't really an issue, aside from the lust in his eyes. It's sad when the alien plotting to conquer the world is the least of your worries.

But Dib noticed more and more that Ms. Olive seemed to be avoiding him, and not in the hateful way Dib was used to being ignored. It almost seemed like she was afraid of Dib. On Thursday, he he finally nutted up and confronted her about it.

"Um, Ms. Olive?" he approached her in the classroom during lunch. "Can I ask you some uncomfortably personal questions?"

"Hmmm, well. Okay, sweetie," replied Ms. Olive. "Just don't ask for my weight! Hehehehe!"

"RIGHT, uh, yeah," Dib continued. "Anyway, how exactly did you get this job position? Did you volunteer? Did Ms. Bitters recommend you? Or were you...SENT?"

"Hehehe!" Ms. Olive ruffled Dib's hair yet again. "Oh, honey, you shouldn't be worrying about big grown-up things like THAT! Hohoho! Let's just say...I needed a break from my old line of work."

Dib was ready to ask another question, but Ms. Olive shooed him off to his seat. It irritated Dib that he was being treated like a five-year old by this woman. (even if it was better than how most people treated him)

"Alright, I didn't find out much the nice way. Now I'm doing this the paranormal investigator way."

XXXXXXXXXXXXXXXXXXXXX

"I somewhat regret doing this the paranormal investigator way." murmured Dib as he crept through the air vent. He was getting grease and grime all over his cool jacket.

But it was all gonna be worth it when he figured out what Ms. Olive was up to.

"Stealth! St-st-stealth! Steeealth!" he sang to himself, which wasn't very stealthy at all.

Dib kept on crawling until he figured he was above the teachers' lounge. He peered down through the grates of the vent and saw Ms. Bitters and Ms. Olive. Jackpot.

"...what are they talking about?"

"I don't know. I can't hear anyth- -AH!" squeaked Dib. "Zim?! What are you doing up here?! Trying to break into the teachers' lounge?"

"Well, what are YOU doing?" growled Zim.

"Not breaking in! I'm SPYING, that's totally different! Just go away before you get us both caught."

"No! I need to see Ms. Bitters!" Zim stuck his PAK legs out and began loosening the vent's screws. "She should be experiencing contortions any minute!"

"It's conTRACtions, you moron! And you're gonna jeopardize my mission!" Dib tried to pull the PAK legs away, but to no avail.

Within seconds, the vent had been removed, and Zim stuck his head down out of the ceiling.

"Ms. Bitters!" he called. "Hey! Hey! It's me, Zim! I'm here to help you pass baby! Don't worry, I brought a wrench! Ms. Bitters?! MS. BITTEEERS! I think she's ignoring me. That, or she's been entered the paralysis stage of her labor, in which case I brought this wrench for nothing."

"Y'know, I'm honestly surprised this air vent has held up this long. I mean, you'd that by now it would've collapsed under our combined- -WAAAAGH!"

As if on cue, the vent collapsed and the two went tumbling down onto the teachers' lounge floor. Zim let out a slight noise of arousal when Dib landed on top of him, causing the boy to disgustedly bolt to his feet.

"And just what are you two doing here?" Ms. Olive stepped up to him with her hands on her hips. "Well?"

"Uhh..." Dib looked around the room for an excuse. "Cabinet...copy machine...coffee maker?"

"...what?"

"Dangit, that usually works in the movies."

Zim had a better reason. "We were worried about Ms. Bitters."

"Ms. Bitters?" Ms. Olive glanced at her. "Why were you worried about her?"

"She's pregnant, you fool!" Zim snapped, causing Dib to facepalm.

"P-Pregnant?" sputtered the substitute before bursting into giggles. "You silly! Ms. Bitters isn't pregnant, not at all! I'm the one with a bun in the oven!"

Dib's eyes widened. "YOU?"

"That's right!" Ms. Olive patted her stomach. "I'm just a few weeks along!"

"OHHHHHHhhhhhh...oh," Dib said in disappointment.

He knew that pregnant women were known to act strangely. Ms. Olive wasn't any kind of paranormal entity, she was just a nice, normal, substitute teacher with a baby on the way. Dib felt like such an idiot for thinking she was suspicious.

He scratched the back of his head, embarrassed. "Well...you know, you really shouldn't be working while you're pregnant..."

The boy awkwardly turned to leave, but Zim was unconvinced.

"YOU'RE pregnant, huh? Well! ZIM shall be the judge of that!"

Ms. Olive stood aghast as Zim suddenly knelt and peeked under her skirt. "Wh-What do you think you're doing?!"

"Checking for larval sacks!" he replied.

Dib shook his head and reached for the doorknob.

"AH! There they are," Zim said before joining Dib at the door. "Her story checks out! And her larval sacks look pretty big; she's probably due soon."

"Seriously, Zim, what are you on? Humans don't have larval sacks between their legs!"

"Well, she does!"

"Huh?" Dib did an about face.

Ms. Olive suddenly clutched her abdomen and let out and agonizing groan. Zim and Dib looked on in horror as the flesh of her legs fanned out and stretched across the majority of the teachers' lounge. By the goo-covered lumps beneath her skin, one could assume these were larval sacks, and one would be right.

"You...you're an alien?!" cried Dib.

"Alright, get yourself ready for this exposition dump. My species is impregnated by HATRED. I discovered that giving birth would cost me my life (literally), and chance would have it I wasn't too popular on my home planet, so I fled before things could get worse. After scouring the universe for a place to begin anew, I stumbled upon your planet. My species may look identical to yours, but we possess special powers. I used my songs to hypnotize your class into adoring me, and preventing gestation. But you and your little green friend had to slip through the cracks..."

"He's not my friend."

"Whatever! It must've been your inorganic makeup that saved you. My powers don't affect test tube babies."

"Huh..."

While Dib was 100% human, he was not actually "born". His father, Professor Membrane, had spliced his own DNA with sample DNA from some random lady, and that was how he and Gaz came to be.

And of course, Zim was preserved in a birthing tube on Irk until he had matured enough to join the military, so he wasn't actually born either.

"And so, I am slain, like the runt of the litter...please, my offspring...avenge me..."

In a disgusting, slimy expulsion, Ms. Olive's body was lost in the sea of her newly-lain eggs. Within seconds, the newborns hatched, emerging as babies with tiny bodies and huge heads. The fifty or so of them levitated into the air and peered down at the corpse of their mother.

"You...BOUNDER!" They turned on Dib, all speaking one. "For our mother, we shall destroy you ALL! ...in about 300 years, when we're fully matured. Until then! FAREWELLLL!"

With that, all the disproportionate babies flew up through the roof to train up for the day they'd return and annihilate humanity.

Dib sighed a sigh of relief. Then he turned to Zim, who looked pretty shaken up.

"Th...That was...DISGUSTING," the alien shuddered out. "My eyes...humans are the most repulsive creatures I've ever..." He stopped to throw up all over the floor.

"No, you idiot!" snapped Dib, wiping drops of vomit from his jacket. "Ms. Olive wasn't a hu...actually, never mind."

"Wait a minute..." Zim said in thought. "If it turns out Ms. Bitters was never really pregnant, then why is she paralyzed like that...?"

He and Dib slowly turned to face the old teacher. They both jumped a bit as she spoke up.

"I wasn't paralyzed, you ninny. I was just on vacation. Now I've come back and I instantly regret that decision."

"Welcome back, Ms. Bitters!" Zim and Dib cried joyfully.

"AH! The sounds of happy children!" She held her ears in pain. "IT BURNS!"

* * *

(A/N: Hoo! This is another one-shot I've been sitting on for forever! Feels good to have finally posted it! Strange how I just so happened to finish after the latest issue of the comic was all about Ms. Bitters...but I've plugged that enough!

Not sure how proud I am of this, maybe I bit off more than I could chew? But a mouthful is better than a morsel. Please review and fave telling what you thought. Back to the ZATR!)


End file.
